It is known that sesamin contained in sesame seeds, sesame protein and sesame oil has various properties such as cholesterol-lowering, antihypertensive, anti-oxidizing, liver-protective, and fat metabolism-controlling properties (Non Patent Document 1).
The method for the extraction or refining of sesamin and episesamin having no taste or odor, and for their application to foods and drinks (Patent Document 1) is known. However, the above method should have problems in cost and processes since the refining and extraction of sesamin and episesamin are required. Furthermore, stability, production properties and taste shall be necessarily examined with respect to each of the foods or drinks as the above substances will need to be added to them.
On the other hand, an invention is known, which relates to an agent for lowering body fat comprising dioxabicyclo [3.3.0] octane derivatives including sesamin as an effective ingredient (Patent Document 2). The invention also comprises a synthesis method in addition to extraction and purification of the above compounds. The invention further comprises a highly refined agent having the effective ingredient of 99.5%. In such case, however, more serious problems shall occur in cost and processes as well as in their addition to the foods.
A method for extracting sesame lignans with a high purity and yield under a supercritical condition is also published (Patent Document 3).
Patent Document 1: Japanese Patent Application Publication Hei03 (1991)-53866
Patent Document 2: Japanese Patent Application Publication 2000-309533
Patent Document 3: Japanese Patent Application Publication 2000-159787
Non Patent Document 1: Yoshiko Toyoda: Japan Food Science p.41-45, 2000-1
Generally, sesame oil is classified into parched sesame oil prepared by parching followed by milling by means of pressing (squeezing) and/or extraction, and refined (purified) sesame oil prepared by milling followed by refining like usual vegetable oil. Parched sesame oil is utilized to actively give sesame taste or flavor mainly to Chinese and Japanese dishes. As sesame oil contains a very small amount of lignans, it is advisable to take sesame oil in the form of the refined one that is more suitable for general purposes rather than of parched one for the purpose of actively ingesting the lignans.